4U THE PARALLEL ROADS OF 
was familiar with all this when I found after¬ 
wards appearances corresponding exactly to 
those which I had investigated in the home 
of the present glaciers. I could therefore say, 
and I think with some reason, that “ this also 
is the work of the glacier acting in ancient 
times as it now acts in Switzerland.” 
There is another character of glacial action 
distinguishing it from any abrasions caused by 
water, even if freighted with a large amount 
of loose materials. On any surface over which 
water flows we shall find that the softer mate¬ 
rials have yielded first and most completely. 
Hard dikes will be left standing out, while 
softer rocks around them are worn away,— 
furrows will be eaten into more deeply, — fis¬ 
sures will be widened, — clay-slates will be 
wasted, — while hard sandstone or limestone 
and granite will show greater resistance. Not 
so with surfaces over which the levelling plough 
of the glacier has passed. Wherever softer 
and harder rocks alternate, they are brought 
to one outline; where dikes intersect softer 
rock, they are cut to one level with it; where 
rents or fissures traverse the rock, they do not 
seem to have been widened or scooped out more 
